Short stature and growth hormone use in pediatric hemodialysis patients

The Role of Growth Hormone in Chronic Kidney Disease

Growth hormone (GH) has become a critical therapy for treating growth delay and failure in pediatric chronic kidney disease. Recombinant human GH treatment is safe and significantly improves height and height velocity in these growing patients and improved growth outcomes are associated with decreased morbidity and mortality as well as improved quality of life. However, the utility of recombinant human GH in adults with chronic kidney disease and end-stage renal disease for optimization of body habitus and reducing frailty remains uncertain. Semin Nephrol 41:x-xx © 2021 Elsevier Inc. All rights reserved.

[Recombinant human growth hormone treatment in short children with renal disease--our first experience]

INTRODUCTION

Growth retardation is a hallmark of chronic illnesses such as chronic kidney disease in children, and it is associated with increased morbidity and mortality. The growth hormone (GH) resistance observed in uraemia can be overcome by supraphysiological doses of exogenous GH.

OBJECTIVE

We would like to present our first results of recombinant human growth hormone (rhGH) treatment, mainly in children on haemodialysis.

METHODS

Sixteen children, aged 4.5-17.1 years (mean age 11.25 +/- 3.57) with height below -2.0 standard deviation score (SDS) for age or height velocity below -2.0 SDS for age, were selected to receive rhGH therapy at our Nephrology and Haemodialysis Department. Most of them were on haemodialysis (14 children) with mean spent time 2.88 +/- 2.68 years (0-9 years) before the initiation of rhGH therapy. One half of patients were prepubertal (8 children) and the second half were in early puberty (testicular volume between 4 and 8 ml for boys and breast development B2 or B3 in girls). All patients received 28-30 IU/m2 rhGH per week by daily subcutaneous injection. The year before rhGH therapy served as a control period.

RESULTS

During the first year of treatment, mean height velocity in haemodialysis patients increased from 2.25 cm/year to 6.59 cm/year (p < 0.0001) and in the second year it was 5.25 cm/ year (p = 0.004). The mean height SDS in haemodialysis children did not improve significantly during the first year of rhGH treatment (from -3.01 SDS to -2.77 SDS, p = 0.063). Neither weight nor the body mass index varied compared with the pretreatment period. Two patients developed worsened secondary hyperparathyroidism and were excluded from the study, but the relationship with rhGH remains uncertain.

CONCLUSION

Mean height velocity significantly improved during rhGH therapy in haemodialysis patients. No significant side-effects were observed in children during three-year treatment with GH.

Clinical outcomes in pediatric hemodialysis patients in the USA: lessons from CMS' ESRD CPM Project

Although prospective randomized trials have provided important information and allowed the development of evidence-based guidelines in adult hemodialysis (HD) patients, with approximately 800 prevalent pediatric HD patients in the United States, such studies are difficult to perform in this population. Observational data obtained through the Center for Medicare & Medicaid Services' (CMS') End Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) Project have allowed description of the clinical care provided to pediatric HD patients as well as identification of risk factors for failure to reach adult targets for clinical parameters such as hemoglobin, single-pool Kt/V (spKt/V) and serum albumin. In addition, studies linking data from the ESRD CPM Project and the United States Renal Data System have allowed evaluation of associations between achievement of those targets and the outcomes of hospitalization and death. The results of those studies, while unable to prove cause and effect, suggest that the adult ESRD CPM targets may assist in identifying pediatric HD patients at risk for poor outcomes.

Relationship between serum parathyroid hormone and trace elements (serum zinc and magnesium) in hemodialyzed chronic renal failure children

Secondary hyperparathyroidism and trace elements' metabolism disturbances are common, important, and treatable complications of chronic renal failure (CRF).The relation between parathyroid hormone (PTH) and some trace elements in CRF patients on hemodialysis is still not completely elucidated. The aim of this work is to determine the serum levels of PTH and the trace elements zinc (Zn) and magnesium (Mg) in children with CRF under hemodialysis. The relation between PTH and those trace elements will be investigated. The study included 24 children (15 males and nine females) with CRF on regular hemodialysis. Also, 15 healthy age-matched children were included as control group. Serum levels of PTH, zinc, and magnesium were determined in all cases and controls. PTH and magnesium levels in patients were significantly higher than controls. Serum zinc levels were significantly lower than controls. There was a significant negative correlation between serum levels of PTH and zinc as well as an insignificant negative correlation between PTH and serum magnesium in CRF patients. Elevated PTH may play a role in the pathogenesis of hypozincemia. However, this is another negative report on the relation between PTH and serum Mg in children with CRF.

Growth hormone treatment in short children with chronic kidney disease

Growth hormone (GH) has been used for treatment of impaired growth in children with chronic kidney disease (CKD) for nearly 17 years. Controlled and open-label studies have shown that GH is highly effective in improving growth velocity and adult height. The growth response is negatively correlated with age and height at start and time spent on dialysis treatment; it is positively correlated with dose and duration of treatment and the primary renal disease (renal hypodysplasia). In children with renal transplants, corticosteroid treatment is an additional factor negatively influencing spontaneous growth rates. However, GH treatment is able to compensate corticosteroid-induced growth failure. GH treatment improved final height by 0.5-1.7 standard deviation score (SDS) in various studies, whereas the control group lost about 0.5 SDS in comparable time intervals. These variable results are explained in part by the factors mentioned above. The adverse events are comparable to those in non-CKD children treated with GH.

CONCLUSION

GH treatment is safe and highly effective in improving growth and final height of short children with all stages of CKD. The highest treatment success is obtained if treatment is started at an early age and with relatively well-preserved residual renal function and continued until final height.

Frequent hemodialysis with NxStage system in pediatric patients receiving maintenance hemodialysis

Recent evidence from adult hemodialysis (HD) patient studies reveal improved biochemical control and reported health-related quality of life after transition from conventional thrice weekly to daily home maintenance HD treatment. Published pediatric frequent dialysis experiences demonstrate similar improvement but all used conventional HD machines, which employ a treated municipal water supply, thereby frequently exposing patients to proinflammatory components. We report our pediatric experience with six-times-weekly HD using the NxStage system, which uses sterile dialysis fluid to provide dialysis in the home or center setting. Four patients (weight range 38-61.4 kg) completed the 16-week study. Patients exhibited progressive reductions in casual pretreatment systolic and diastolic blood pressures, discontinuation of antihypertensive medications, and decreased blood pressure load by ambulatory blood pressure monitoring. Mean serum phosphorus improved without change in phosphorus binder medication, and all three patients with a normalized protein catabolic rate <1 g/kg per day at the beginning of the study improved to a normalized protein catabolic rate (nPCR) of >1.1 g/kg per day. Patients reported no adverse effects. Variable changes in proinflammatory cytokine levels were observed. We suggest that frequent HD with the NxStage system be considered for children who would benefit from home-based maintenance dialysis.

Linear growth in pediatric hemodialysis patients

Growth is an important outcome in pediatric kidney disease. We aimed to identify factors associated with growth in pediatric hemodialysis (HD) patients. Height standard deviation scores (Ht SDS) of pediatric HD patients with consecutive height measurements in the ESRD Clinical Performance Measures Project were calculated. Multiple linear regression determined the effect of factors on Ht SDS change/year. Four hundred and seven patients were included. Median age was 15.2 years (interquartile range 13.2-16.5 years); 44% were girls, and 27% were black. Of patients observed, 66% had growth hormone (GH) data, and of those, 29% were prescribed GH. Mean change in Ht SDS/year was -0.10+/-0.71. After adjustment, decreasing Ht SDS was associated with younger age (-0.2/year for <13 vs. >or=13 years; p<0.0001), longer duration on dialysis (-0.03/year for >or=6 months vs. <6 months; p<0.01), and higher normalized protein catabolic rate (nPCR) (-0.02/year per 0.1; p<0.05). Improved growth was seen in girls (0.10/year; p<0.01) and in those with lower Ht SDS (0.03/year per 0.5 decrease; p<0.001). Hemoglobin, GH use, and adequacy were associated with neither positive nor negative changes in Ht SDS. Growth retardation while on HD was most pronounced in patients who were young, male, had longer durations on HD, had higher nPCR, and had higher baseline Ht SDS.

Anemia and growth status in pediatric patients receiving maintenance dialysis after a failed renal transplant course: an NAPRTCS report

We conducted a retrospective review of the North American Renal Transplant Cooperative Study (NAPRTCS) Registry transplant and dialysis arms to assess anemia and growth patterns in children who returned to dialysis after a failed renal transplant from January 1, 1992 to February 3, 2004. Of the 1807 potential study subjects, 1451 had transplant removal data (TxIn vs. TxOut) available for analysis. Four hundred and twenty-one of 1451 patients (29%) had a transplant nephrectomy at the time of entry into the NAPRTCS Registry Dialysis arm. Anemia rates steadily decreased from 72.2% at 30 days after dialysis initiation to 59.5% at 12 months after dialysis initiation. Factors associated with anemia at 30 days after dialysis initiation included hemodialysis, lack of Epo use, and patients who comprised earlier study era cohorts. At one yr after return to dialysis, earlier study cohort era was the only factor associated with anemia status. Patients did not demonstrate significant improvement in height SDS over the course of the study (-2.17 at day 30 to -2.32 at 24 months). The high anemia, poor growth, and low recombinant human growth hormone utilization rates in a group of patients followed longitudinally as they transition from renal transplant to dialysis should cause the pediatric nephrology community to reassess the processes in place to provide optimal care to pediatric end-stage renal disease patients.